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M. lB. MILLS.

` AIR PRESSURE APPARATUS PoR GARBRAKRS. No. 497,475. Patented'MRy 16,1893.

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M..B. MILLS'. AIB. PRESSURE APPARATUS PoR GAR BRAKBS.-

No. 497,475. A Patenteamay 16, 1893.

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M. vB. MILLS.

AIR PRESSURE APPARATUS POR GAR BRAKES. No. 497,475. Patented May 16, 1893.

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MoE'rIMER B. MILLS, OE CHICAGO, ILLINOIS, ASSICNOR To THE MILLS IMPRovED PNEUMATIC BRAKE COMPANY, OE SAME PLACE.

AIR-PRESSURE APPARATUS FOR CAR-BRAKES.

SPECIFICATION forming part of Letters Patent No. 497,475, dated May 16, 1893.

Application iiled April 25, 1892. Serial No. 430,571. (No model.)

To all whom t may concern,.-

Beit known that I, MORTIMER B. MILLS, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented anew and useful Improvement in Air-Pressure Apparatus for Car-Brakes, of which the following is a specification.

My invention relates to an improved apparatus for usein applying the brakes of cars, at the will of the operator, by converting the energy of the car in motion into air-pressure for setting the brakes.

The object of my invention'is to provide especially effective mechanism for exerting the power of the moving car upon the airpressure generating mechanism whence it shall be applied directly to setting the brakes; and to this end my invention consists in the general construction of my improved apparatus, and it also consists in details of construction and combinations of parts.

In the accompanying drawings- Figure l is a plan view of my improved air-compressing apparatus applied to an axle. Fig. 2 isa section of the same taken on the line 2 of Fig. l and viewed in the direction of the arrow.

' Fig. 3 is a section taken on the line 3 of Fig.

1 and viewed in the direction of the arrow. Fig. 4 is a section taken on the line 4 of Fig. l, Viewed in the direction of the arrow and enlarged. Fig. 5 is a diagrammatic plan view of the entire apparatus as connected to the brake-mechanism of a car.

A (Fig. 3) represents the base-portion of a car, which may be a street-car, for which my improvement is particularly designed, or a railway car.

On a rotary axle B of the car is secured, to rotate with it, an eccentric C loosely surrou nded by its strap C provided with a guide-pin r extending transversely of the strap from a boss r on one side of its periphery.

E is a slotted extension of the piston-rod E of an air-pump F, supported in horizontal position at a right-angle to the axle B below the car, as by being flexibly or loosely suspended through the medium of links q, and connected with bifuroated arms p (Fig. l) fastened to opposite sides of the pump cylinder and thence extending to and embracing the axle B on which they are rigidly supported at their ends through the medium of collars o surrounding the axle and Within which it rotates. The slotted extension E of the pistonrod embraces the axle B and guide-pin fr, on one side of the eccentric C; land it carries at one side a suitable stop, or dog G pivoted to one side of the piston-rod extension near its free end, being adapted to be thrown with its free end into and out of engagement with the guide-pin r. The means for controlling the adjustment of the dog G may be a chain n connected with it near its free end from a bell-crank lever m conveniently accessible to the operator on the car. The dog may tend vonly by its gravity to engage the guide-pin r, or it may be assisted in its tendency by a spring n', indicated by a dotted line representation -in Fig. 3, being connected at one end with an earn on the dog and at its Opposite end with an eye o on the piston-rod extension vE.

From the foregoing the operation of the apparatus, as thus far described, will 'be understood to be as follows: Normally the dog G is raised out of engagement with the pin r, and then as the axle B rotates in the motion of the car the eccentric C revolves and moves its strap C with the guide-pin fr back and forth in the slot of the piston-rod extension E, without working the piston. When, however, the operator desires to apply the brakes,

he manipulates the lever m in a manner to Y permit the dog G to assume the position inY which it is illustrated of engaging the pin r, whereby the action of the eccentric reciprocates the extension E and with it the pistonrod E', whereby the piston E2 is reciprocated back and forth in the cylinder of the pump. It is preferred that each stroke of the piston shall draw air into the cylinder at one side and force the previously admitted air out un- Y IOG ner to promote the stoppage by the resistance of Workin g the pump. The air-pressure holds the brakes set till the dog G is raised by properly turning the lever m, when the Weight of the brake-shoes (which maybe assisted by the releasing-springs usually provided) causes them to drop from their positions of bearing against the wheels after the movement of the lever m by its connection t with the handlef of an ordinary two-way valve f, has turned the valve to open to the outer air the feedpipe to the cylinder D; and, as will be understood, turning the lever m to engage the dog G with the stop fr turns the valve f to close the passage. The position of thevalve f is indicated by the reference-letter w in Fig. 5.

To prod uce the desired air-com pression with each stroke of the piston E2, I provide at 0pposite ends of the cylinder of theair-pump F double check-valve devices K and K of the construction illustrated in Fig. 4, and each comprising two connected chambers 7c and 7s', divided by a diaphragm k2 seating a downwardly closing check-valve e' between the tWo chambers and near the outlet-end t" of the device of the chamber, 7.3 having a combined inlet and outlet opening g2, near Which is seated, over an air-inlet g', a downwardly closing valve g. The devices K and K are connected, each at its opening g2, respectively with the opposite ends of the pump-cylinder, and from their openings il lead the conducting pipes i2 and t3, which unite at m, whence the pipe i3 continues into the compressed-air cylinder D to permit the pump to force the air against the piston therein.

By the foregoing construction, as will be observed, the powerof the rotating aXleBwhich is employed to Work the air-pressure to set the brakes is immediately resisted from the beginning of the operation by the air-pressure mechanism, thereby employing throughout the operation the inertia of the moving car to bring it to a standstill.

The details of the valves on the pump and of other parts of myimproved apparatus may be variously departed from without thereby departing from my invention. lIence I do not Wish to be understood as limiting my invention thereto.

lVhat I claim as now, and desire to secure by Letters Patent, is-

In combination with a car and its brakesystem, air-pressure apparatus for operating the brakes, having an eccentric C on au axle D with its surrounding strap C provided With a guide-pin 0', an air-pump F having its cylinder flexibly suspended from the car-body and connected at opposite sides with corresponding ends of arms p, the opposite ends of which are firmly fastened to collars o surrounding the axle, and the piston-rod E ot' the pump being provided With the slotted extension E embracing the said axle and guidepin and carrying a pivotal dog G, and a suitable lever connected with the dog for adjusting it into and out of engagement With the guide-pin, substantially as and for the purpose set forth.

MORTIMER B. MILLS.

In presence ol`- M. J. FROST, J. N. HANsoN. 

